Quick question: Does this work with Spotify's API, or do users need to export their data manually? And can you see trends over time (like "your taste got more mainstream in Q4" )?
The "how mediocre is your taste" angle is hilarious and probably more honest than Spotify's version!
The app uses the official Spotify Web API (https://developer.spotify.com/documentation/web-api), all the user need to do is log in and everything should be set up automatically.
Right now the visualization is just a static snapshot, so there's no comparison between quarters yet. Although, this is surely a really really cool idea which I might look into adding in the future if this gets some traction.